The Japan Meteorological Agency (JMA) reported that activity continued at Shinmoedake (Shinmoe peak, a stratovolcano of the Kirishimayama volcano group) during 8-15 September. The number of volcanic earthquakes located beneath Shinmoedake, first detected in late October 2024, continued to be frequent; volcanic tremor was last detected on 4 September. Gas-and-steam plumes rose as high as 500 m above the crater rim and fumarolic plumes rose as high as 20 m along the fissures on the W flank. Sulfur dioxide emissions were low on 12 September, averaging 300 tons per day. The Alert Level remained at 3 (on a 5-level scale) and the public was warned to exercise caution within 3 km from Shinmoedake Crater.

Geological Summary. Kirishimayama is a large group of more than 20 Quaternary volcanoes located north of Kagoshima Bay. The late-Pleistocene to Holocene dominantly andesitic group consists of stratovolcanoes, pyroclastic cones, maars, and underlying shield volcanoes located over an area of 20 x 30 km. The larger stratovolcanoes are scattered throughout the field, with the centrally located Karakunidake being the highest. Onamiike and Miike, the two largest maars, are located SW of Karakunidake and at its far eastern end, respectively. Holocene eruptions have been concentrated along an E-W line of vents from Miike to Ohachi, and at Shinmoedake to the NE. Frequent small-to-moderate explosive eruptions have been recorded since the 8th century.

Source: Japan Meteorological Agency (JMA)